Transcript Ponds and Lakes

Aquatic Ecosystems
Freshwater
Ponds & Lakes
Streams &
Rivers
Wetlands
Marine
Oceans
Coral Reefs
Estuaries
Freshwater
Ponds & Lakes
Streams & Rivers
Wetlands
Freshwater
Only 3% of the world’s
water is fresh
99% of this is frozen or
buried in aquifers
1% is found in lakes,ponds,
rivers or streams
Freshwater - lentic
Freshwater is defined as having a
low salt concentration—usually
less than 1%
Plants and animals in freshwater
regions are adjusted to the low
salt content and would not be
able to survive in areas of high
salt concentration (i.e, ocean)
Ponds and Lakes
range in size from just a few square meters to
thousands of square kilometers
ponds may be seasonal, lasting just a couple
of months (such as sessile pools)
lakes may exist for hundreds of years or
more
may have limited species diversity since
they are often isolated from one another and
from other water sources like rivers and
oceans
Ponds and Lakes
divided into three different “zones”
determined by depth and distance
from the shoreline
littoral zone
limnetic zone
profundal zone
Littoral Zone
Zone close to shore
warmest since it is shallow and can absorb more of
the Sun’s heat
sustains a fairly diverse community, which can
include several species of algae (like diatoms),
rooted and floating aquatic plants, grazing snails,
clams, insects, crustaceans, fishes, and amphibians
the egg and larvae stages of some insects are found
in this zone
vegetation and animals living in the littoral zone are
food for other creatures such as turtles, snakes, and
ducks
Limnetic Zone
near-surface open water surrounded by the
littoral zone
well-lighted (like the littoral zone) and is
dominated by plankton, both phytoplankton
and zooplankton (rotifers)
plankton are small organisms that play a
crucial role in the food chain – most life
would not be possible without them
variety of freshwater fish (nekton) also
occupy this zone
Profundal Zone
Plankton have short life spans—when
they die, they fall into the deep-water
part of the lake/pond
much colder and denser than the other
two
little light penetrates all the way through
the limnetic zone into the profundal zone
animals are decomposers (bentos)
Ponds and Lakes
The Three Layers of a Lake
During Summer Stratification
Atmosphere
Lake Surface
Epilimnion –
Lake bottom
warm, light water
Thermocline –
boundary layer
Hypolimnion –
cold, heavy water
Types of Ponds and Lakes
Ponds and Lakes
Temperature
varies seasonally.
Summer
from 4° C near the bottom to 22° C at the top
Winter
from 4° C while the top is 0° C (ice)
between the two layers is a narrow zone
called the thermocline where the temperature
of the water changes rapidly with depth
Ponds and Lakes
Temperature
varies seasonally.
Summer
from 4° C near the bottom to 22° C at the top
Winter
from 4° C while the top is 0° C (ice)
between the two layers is a narrow zone
called the thermocline where the temperature
of the water changes rapidly with depth
Ponds and Lakes
during the spring and fall seasons is a
mixing of the top and bottom layers
resulting in a uniform water temperature
of around 4° C
mixing also circulates oxygen
throughout the lake
many lakes and ponds do not freeze
during the winter resulting in the top
layer being a little warmer
Ponds and Lakes
ice can develop on the top of lakes
during winter
blocks out sunlight and can prevent
photosynthesis
oxygen levels drop and some plants
and animals may die
called "winterkill."
Ponds and Lakes
Temperate Lakes Go Through an
Annual Cycle Based on Changes in
Climate Over the Four Seasons
Annual Cycle Of A
Temperate Lake
Lake Succession
Oligotrophic lakes
•young; low in nutrients & productivity
•clear & sparkling blue
•deep water is oxygen-rich
Eutrophic lakes
•older; nutrient rich & high in productivity
•green & murky
•O2 often depleted in deep water during
summer
Nutrients in sewage & agricultural runoff
speed eutrophication.
Process of Eutrophication
•Defined as the enrichment of a body of water and
subsequent increase in productivity.
•Occurs naturally but at a slow pace over
geological time
•Human activities greatly accelerate the process of
eutrophication:
Increased nutrient input from fertilizer
mismanagement
Nutrients associated with sewage
Ponds and
Lakes
Streams & Rivers-lotic
bodies of flowing water moving in one
direction
found everywhere—they get their start
at headwaters, which may be springs,
snowmelt or even lakes
travel all the way to their mouths,
usually another water channel or the
ocean
Watershed
describes an area
of land that
contains a common
set of streams and
rivers
drains into a single
larger body of
water, such as a
larger river, a lake
or an ocean
Streams & Rivers
characteristics change during the
journey from the source to the mouth
temperature is cooler at the source
than it is at the mouth
water is also clearer, has higher
oxygen levels, and freshwater fish such
as trout and heterotrophs can be found
there
Streams & Rivers
Towards the middle part of the
stream/river, the width increases, as
does species diversity—numerous
aquatic green plants and algae can be
found
Streams & Rivers
toward the mouth the water becomes murky
from all the sediments that it has picked up
upstream
decreasing the amount of light that can
penetrate through the water
less light
less diversity of flora
lower oxygen levels
fish that require less oxygen, such as catfish
and carp, can be found
Streams & Rivers
toward the mouth the water becomes murky
from all the sediments that it has picked up
upstream
decreasing the amount of light that can
penetrate through the water
less light
less diversity of flora
lower oxygen levels
fish that require less oxygen, such as catfish
and carp, can be found
Streams & Rivers
Distributary – A smaller channel
that takes water away from the
main stem river.
Flow
Mississippi River
(Main Stem)
Atchafalaya River
(Distributary)
River Channel
Deep Holes
Sand Bars
Oxbow Formation
•Water flows at different speedsfastest at outside banks
•Inside banks fill with sediments
•This creates the river to bulge
out until a loop is formed
•River meanders through flat
terrain
•Eventually enough deposits are
laid to join the beginnings and
ends of the loop (neck) diverting
the river
•With time the seal is closed off
thereby creating a horseshoe
shape (oxbow)
Oxbow Formation
Streams &
Rivers
Wetlands
Wetlands are areas of standing
water that support aquatic plants
Marshes, swamps, and bogs are
all considered wetlands
Wetlands
Plants
adapted to the very moist and humid
conditions are called hydrophytes
Pond lilies
Cattails
Tamarack
Gum
Sedges
Black Spruce
Cypress
Wetlands
highest species diversity of all ecosystems
many species of amphibians, reptiles, birds
(such as ducks and waders), and furbearers
can be found in the wetlands
not considered freshwater ecosystems as
there are some, such as salt marshes, that
have high salt concentrations—these
support different species of animals, such
as shrimp, shellfish, and various grasses
River Otter
Wetlands
Crayfish
Catfish
Damselfly
Dragonfly
Snails
Leech
Bluegill
Sculpin
Minnow
Snakes
Frog
Great Blue Heron
Canadian Goose
Mayfly
Bass
Turtle
Aquatic Ecosystems
Marine
Oceans
Coral Reefs
Estuaries
Marine
cover about three-fourths of the Earth’s
surface and include oceans, coral reefs,
and estuaries
algae supply much of the world’s
oxygen supply and take in a huge
amount of atmospheric carbon dioxide
evaporation of the seawater provides
rainwater for the land
Oceans
largest of all the ecosystems
dominate the Earth’s surface
separate zones
Intertidal
Pelagic
Abyssal
Benthic
great diversity of species
richest diversity of species even though it
contains fewer species than there are on land
Oceans
Intertidal Zone
where the ocean meets the land
sometimes submerged and at other
times exposed
waves and tides come in and out
communities are constantly
changing
Intertidal Zone
rocky coasts
stratified vertically
Where only highest tides reach
 a few species of algae and mollusks
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submerged during high tide
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more diverse array of algae and small animals,
such as herbivorous snails, crabs, sea stars, and
small fishes
bottom of the intertidal zone
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only exposed during the lowest tides, many
invertebrates, fishes, and seaweed can be found
Intertidal Zone
sandier shores
not as stratified
waves keep mud and sand constantly
moving
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very few algae and plants can establish
themselves—the fauna include worms,
clams, predatory crustaceans, crabs, and
shorebirds.
Wave Regions
much stronger than wind
decide what grows where
shores classified by amount of wave action
Exposed shores – receive full brunt of the ocean for most or at
least some of the time
Semi-exposed shores – sheltered by barrier islands but still
have to cope with waves
Sheltered shores – shelter of peninsulas and inshore islands
Enclosed shores
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river mouths and estuaries
completely sheltered by either a protective rocks or a sand bar
Pelagic – Open Ocean
waters further from the land, basically
the open ocean
generally cold though it is hard to give a
general temperature range since, just
like ponds and lakes, there is thermal
stratification with a constant mixing of
warm and cold ocean currents
Epipelagic – Open Ocean
extends down to around 200m
lowest depth that light can penetrate
flora in the epipelagic zone include
surface seaweeds
fauna include many species of fish and
some mammals, such as whales and
dolphins
many feed on the abundant plankton
Mesopelagic Zone
http://oceanlink.island.net/oinfo/deepsea/meso.html
"twilight zone" of the ocean
photic zone above
darkness below
food becomes scarce – some animals
migrate up to the surface at night to feed
rely on food that falls down from above
eat each other

sometimes the only things to eat may be bigger
than the hunter
• developed long sharp teeth,
• expandable jaws and stomachs
Big Scale - ambush predator
ctenophore – related to jellyfish
cilia can be illuminated
Firefly squid
three kinds of photophores
Hatchet Fish
only a few inches long
Viperfish
specially adapted hinged skull
Dragonfish - stomachs hold big meals
Snipeel
up to 1.2m
Siphonophores are colonies of animals
related to jellyfish
best known is Portugese Man of War
http://oceanlink.island.net/oinfo/deepsea/meso.html
Bathypelagic Zone
extends down from 1000 to 4000m
only light is from bioluminescent organisms
only food is what trickles down from above, or
from eating other animals
water pressure at this depth is considerable
(~100 – 400 atmospheres)
most animals are either black or red in color
very little blue/green light penetrates this deep –
red is not reflected and looks black
Narcomedusa
Vampire Squid
Snake Dragon
Angler Fish
Amphi - crustacean
Ctenophore – voracious predator
Deepstaria very slow swimmers,
no tentacles, close flexible bells
(up to a meter across) around
their prey
Big Red
grows to over
a meter across
Abyssopelagic Zone - the Abyss
4000m to the sea floor
only zone deeper than this is the hadal
zone
areas found in deep sea trenches and
canyons
home to pretty inhospitable living
conditions
near- freezing temperatures
crushing pressures
Deep Water Squid
Basketstar
Sea Pig
Sea Spider
Shrimp
Winged Sea Cucumber
Medussa
Deep Sea Smoker - 648°F
Deep-sea Anemone
Hydrothermal Vent
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Ballina Angelfish
Beaked Salmon
A deepsea anglerfish (no common name)
Duckbilled Eel
A fanfin anglerfish
Fangtooth
Gilbert's Halosaur
Gulper Eel
Hammerjaw
Largescale New Laternfish
Longray Spiderfish
Portuguese Dogfish
Sharpnose Sevengill Shark
Short-tail Torpedo Ray
Silver Lighthouse Fish
A snaggletooth (no common name)
Snubnosed Eel
Southern Spineback
Sparkling Slickhead
Spiky Oreo
Stoplight Loosejaw
Triplewart Seadevil
Viperfish
http://www.amonline.net.au/fishes/about/fieldwork/norfanz/
The Coral Reef Biome
A Look at a
Marine Biome
Created by
Terri Street
What Is a Coral Reef?
A structure formed by coral polyps,
tiny animals that live in colonies.
Coral polyps form a hard, stony,
branching structure made of
limestone.
New polyps attach to old coral and
gradually build the reef.
Types of Coral Reefs
Fringing reefs
Submerged platforms of living coral
extending from the shore into the sea
Barrier reefs
Follow the shore but are separated from
it by water
Great Barrier Reef is world’s largest
Types of Coral Reefs
Atolls
Ring-shaped islands of coral in open sea
Form on submerged mud banks or
volcano craters
Surround a seawater lagoon
Channels connect lagoon to the sea
A World of Coral Reefs
= Coral Reef
Coral Reef Climate
Usually found near land in shallow,
warm salt water
Lots of light
Tropical temperatures, averaging 70°85° F
Most coral cannot survive below 65° F
Coral Reef Plants
Phytoplankton
Microscopic
Basis for all ocean
food chains
Coral Reef Plants
Algae
Green
Red
Brown algae
takes many forms
Coral Reef Plants
Seaweed and Sea grasses
Brown seaweed
Sea grass
Shoal grass
Turtle grass
Fascinating Fact: The Great
Barrier Reef
World’s largest coral reef
Over 1257 miles
long
Off the northeast
coast of Australia
Only grows about
one inch per year
The Great Barrier Reef:
Home to…
1500 species of fish
400 different types of coral
4,000 mollusks
500 species of seaweed
215 species of birds
16 species of sea snake
6 species of sea turtle
Whales visit during winter
Coral Reef Creatures
Coral polyps
Tentacles
Digestive
sac
Connecting
filaments
Skeletal body
Coral Reef Creatures
Symbiotic relationships
Coral with
algae
Clown fish
with sea
anemones
Coral Reef Creatures
Tropical fish
Angel fish
John Dory
Butterfly fish
Sea horse
Octopus
Reef shark
Fascinating Fact:
The Sea Horse
Very weak swimmers
Female lays eggs, male carries them
in pouch till birth
Only animal in which the father gives
birth
Body covered with armored plates
Sample Food Chain
Starfish
Coral
Octopus
Zooplankton
Moray Eel
Phytoplankton
Endangered Coral Reefs
Major threats to coral reefs
include:
Ocean pollution
Dredging off the
coast
Endangered Coral Reefs
Other dangers:
Careless collection of coral specimens
Sedimentation
Inhibits growth of coral polyps
 Inhibits algae growth
 Upsets balance of the biome

Estuaries
http://www.epa.gov/owow/estuaries/about1.htm
enclosed body of water formed where
freshwater from rivers and streams flows into
the ocean, mixing with the salty sea water
estuaries and the lands surrounding them are
places of transition from land to sea, and from
fresh to salt water
although influenced by the tides, estuaries are
protected from the full force of ocean waves,
winds, and storms by the reefs, barrier islands,
or fingers of land, mud, or sand that define an
estuary's seaward boundary
Estuaries are semi-enclosed bodies of water where
fresh water from the land mixes with sea water.
Estuaries originate as: drowned
river valleys, fjords, bar-built
estuaries, and tectonic estuaries.
Salinity typically grades from
normal marine salinity at the tidal
inlet to fresh water at the mouth of
the river.
Estuaries can be subdivided into three types based
upon the relative importance of river inflow and
tidal mixing.
Salt-wedge estuaries are dominated by the outflow from
rivers.
Partially-mixed estuaries are dominated by neither river
inflow nor tidal mixing.
In well-mixed estuaries tidal turbulence destroys the
halocline and water stratification.
Because river discharge and tidal flow vary, conditions
within an estuary can also change, being well-mixed when
river flow decreases relative to tidal mixing, to becoming a
salt-wedge estuary at times of maximum river discharge.
The widely fluctuating environmental conditions in
estuaries make life stressful for organisms.
Estuaries are extremely fertile because nutrients are
brought in by rivers and recycled from the bottom because
of the turbulence.
Stressful conditions and abundant nutrients result in low
species diversity, but great abundance of the species
present.
Despite abundance of nutrients, phytoplankton blooms are
irregular and the base of the food chain is detritus washed
in from adjacent salt marshes.
The benthonic fauna strongly reflects the nature of the
substrate and most fishes are juvenile forms living within
the estuary until they mature and migrate to the ocean.
Estuaries
http://www.epa.gov/owow/estuaries/about1.htm
Estuaries are sometimes called “marine
nurseries”
habitats for many juvenile organisms, especially
for fishes
many fish are born and grow up in estuaries
migrate to the open ocean
Lagoons are isolated to semi-enclosed, shallow,
coastal bodies of water that receive little if any
fresh water inflow.
Lagoons can occur at any latitude and their salinities
vary from brackish to hypersaline depending upon
climate and local hydrology.
Bottom sediments are usually sand or mud eroded which
was from the shoreline or swept in through the tidal inlet.
In the tropics, the water column is typically isothermal.
In the subtropics, salinity generally increases away from
the inlet and the lagoon may display inverse flow.
Salt marshes are intertidal flats
covered by grassy vegetation.
Marshes are most commonly found in protected areas
with a moderate tidal range, such as the landward side
of barrier islands.
Marshes flood daily at high tide and then drain through
a series of channels with the ebb tide.
They are one of the most productive environments.
Marshes can be divided into two parts: Low salt
marshes and High salt marshes.
Distribution and density of organisms in salt marshes
strongly reflects availability of food, need for
protection, and frequency of flooding.
Mangroves are large woody trees with a
dense, complex root system that grows
downward from the branches
Mangroves are the dominant plant of the
tropical and subtropical intertidal area
Distribution of the trees is largely
controlled by air temperature, exposure
to wave and current attack, tidal range,
substrate and sea water chemistry
Detritus from the mangrove forms the
base of the food chain